The System on a Chip (SoC) is increasingly common in mobile devices such as smartphones and tablets. A SoC is an integrated circuit comprising multiple components of a computing system. For example, a typical SoC may contain one or more processor cores, a Graphics Processing Unit (GPU), a memory controller, and memory. Some SoCs may also contain components such as radios and basebands for cellular communication, Wi-Fi, GPS, and Bluetooth, etc., as well as a Digital Signal Processor (DSP).
It is desirable to improve power efficiency of SoCs used in mobile devices in order to increase battery life. More particularly, improving power efficiency of SoCs for sensor-related tasks is important because many context-based applications demand the gathering, processing, and fusing (combining data from disparate sensors to derive information) of sensor data from multiple sensors on a continuous always-on basis. Performing these sensor-related tasks on an always-on basis with a general purpose processor core and/or a DSP is overly energy-inefficient.